Granted Patent
Utility
US 5,287,877 · App. 07/986,792
Sewer drain trap primer valve
Inventor:
Rand H. Ackroyd
Patented Case
View Patent ↗
Granted: Feb 22, 1994
Filed: Dec 8, 1992
Inventor
Rand H. Ackroyd
Assignee (at issue)
Watts Investment Company
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.